Computer simulation of xenon dimer formation in a dense inert-gas environment

Abstract

A molecular-dynamics technique has been used to simulate the formation of xenon dimers in either an argon or a helium heat bath. In a typical calculation, the trajectories of two xenon atoms and 14 argon or helium atoms contained in a spherical vessel by a soft-wall potential, are followed as a function of time. Comparisons with xenon dimer concentrations predicted from statistical mechanics, suggest that the model exhibits the type of non-ideal behaviour expected both from inefficient heat bath gases, such as helium, and from solvent systems in general at very high densities. Simulations for a range of temperatures, show that the three-body step leading to xenon dimer formation exhibits a change in mechanism from intermediate complex to energy transfer.